Many automated drill pipe wrenches used to make up or break down wellbore tubulars on drilling rigs are known. Some wrenches comprise two or three rams in opposed relation, each ram having a pair of tong dies or “gripping teeth” to contact, hold and manipulate the tubulars. Unfortunately, the force required to grasp the tubular can score or damage the tubular surface, resulting in premature wearing of the tubular. Further, the die used to contact and grip the tubular become dull (wear down), break, or become displaced over time.
International Patent Application No. PCT/CA2014/000401 describes a drilling rig floor wrench (the '401 Application). The wrench disclosed in the '401 Application comprises a plurality of die blocks that comprise, inter alia, die holders for releasably receiving and securing gripping dies. The dies can be secured in die slots on the front face of the die blocks using threaded screws or nut and bolt assemblies. To replace the dies, a laborer must unthread the screws, or loosen the nuts, such that the bolts are completely withdrawn from the block. Problems arise where the screws or nuts are too tight to be removed manually, the hardware become stripped and cannot be reused, or loose parts become lost due to dropping. Furthermore, replacement of each individual die in this manner can be time consuming.
There is a need for a fast, efficient and easy way to “quick release” (e.g. insert/remove) dies positioned within die blocks on the tong assemblies of automated drill pipe wrenches on the floor of a drilling rig.